KR19980085745A - Valve structure of automobile engine - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a valve that opens and closes the intake valves and the exhaust valves in each cylinder of an automobile engine in a ignition order, and prevents the ribs of the cam and the valve lifter from directly contacting each other. An object of the present invention is to prevent friction and wear of a valve. To this end, the present invention is integrally formed with a cam shaft, and has a cam having an eccentric lobe on one side, and the upper and lower sides of the cam are in contact with the lobe of the cam. In a valve structure of an automobile engine including a valve lifter moved to a valve, a valve of an automobile engine characterized in that a completely spherical ball is inserted into an upper surface of the valve lifter and rotatably mounted in the valve lifter. Provide structure.

Description

Valve structure of automobile engine

The present invention relates to a structure of a valve for opening and closing the intake valve and the exhaust valve in each cylinder of an automobile engine at a time designed in the ignition order.

In general, the valve mechanism of a four-cycle engine is composed of an intake / exhaust valve and a valve opening / closing mechanism for opening and closing the valve. The valve opening area is set to a large speed or acceleration when the valve is opened or closed to improve the engine output. It is necessary to secure a large amount of mixer into the cylinder as large as possible, but if the speed or acceleration of the valve is too fast, the noise increases and the valve does not collide with the valve seat or the movement of the valve follows the shape of the cam. Problems such as damage to the mechanism may occur, so that a large valve opening area should be adopted to solve such problems as much as possible.

On the other hand, the valve opening and closing mechanism of the four-cycle engine is classified into various types according to the position in which the valve is arranged, the type of which is installed in the cylinder head, the cam OHV (overhead) for opening and closing the valve through the push rod and rocker arms valve), valves and camshafts installed in the cylinder head, the cams have an overhead camshaft (OCH) type that opens and closes the valve through the rocker arm, and the double overhead camshaft (DOHC) type and the cylinder opens the valve directly. Valves are provided on both sides or one side of the valve, and there are SV (side valve) types which are rarely used at present.

Here, in any manner, the valve opens and closes the intake and exhaust ports while the valve stem is vertically reciprocated by the cam, and the section for vertically reciprocating the valve is called a lift length.

On the other hand, the valve lifter has a cylindrical shape as a part for converting the rotational motion of the cam shaft into a vertical motion, the upper surface of which is in contact with the cam in a plane, and an inner surface thereof is provided with a concave sheet to which the push rod touches. Or a lifter hole provided in the cylinder head.

However, in addition to the above-mentioned valve lifter, there is a hydraulic valve lifter using hydraulic pressure, and the lifter is provided with a hydraulic chamber between the lifter and the push rod, and the vertical movement of the lifter is applied to the push rod through the hydraulic pressure. Delivered. Such a structure can absorb the thermal expansion of the valve in the hydraulic chamber, thereby eliminating the need for valve clearance and reducing the noise of the valve opening and closing mechanism. This hydraulic valve lifter is also referred to as a valve lash ajuster.

In the conventional valve lash adjuster, an oil-filled portion is formed at an inner upper end of the body, and a substantially U-shaped plunger is fixed at the center of the oil-filled body, and a plunger seat as a piston is formed inside the plunger. It is installed so that it can move up and down in the state which was opened. In addition, such a hole is blocked by the check ball, and the plunger sheet is kept in a fixed state by a spring.

With this configuration, as shown in FIG. 1, when the lobe 2 of the cam 1 presses the valve lifter 3, the entire system presses the valve stem, but at this time, some oil is released around the plunger seat. Will flow. That is, since the force is transmitted in the state where the oil is moving, the valve lifter 3 always moves in close contact with the cam, so that the valve lifter 3 is accurately operated along the shape of the lobe 2 of the cam 1. Also, when the lobe 2 passes and the force is removed, the inner hole of the plunger seat is opened by the check ball to replenish oil, and the system returns to its original state according to the force of the spring.

However, in the related art, as described above, the lobe 2 of the cam 1 and the upper surface of the valve lifter 3 are in direct contact with each other, thereby causing abrasion due to friction with each other. The change of the lift is accompanied, there is a problem that the noise due to friction and degradation of the engine performance due to the valve lift change.

Therefore, the present invention has been proposed to solve such a conventional problem, and by improving the conventional valve structure to prevent the rib and valve lifter of the cam directly contacting to prevent friction and wear of the rib and valve For the purpose of

1 is a perspective view showing a conventional valve operation structure.

Figure 2 is a perspective view showing the structure of the valve lifter according to the present invention.

3 is a front view of FIG. 2;

Explanation of symbols on the main parts of the drawing

One ; Cam 2; Robes

3; Valve lifter 4; ball

In order to achieve the above object, the present invention is an automobile comprising a cam formed integrally with the cam shaft, having a eccentric lobe to one side, and a valve lifter moved up and down by contacting the lobe of the cam at the bottom of the cam In the valve structure of an engine, a complete spherical ball is inserted into an upper surface of said valve lifter, and provides a valve structure of an automobile engine, characterized in that it is rotatably mounted in the valve lifter.

It is also desirable that the cam and lobe have as thin a thickness as possible to reduce the contact surface with the ball mounted on the upper surface of the valve lifter.

EXAMPLE

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention, the same reference numerals are assigned to the same parts as those cited in the prior art, in the present embodiment, to avoid duplication of description again Do not explain.

2 is a perspective view illustrating a structure of a valve lifter according to the present invention, and FIG. 3 is a front view of FIG. 2.

First, according to the present invention, by providing a ball that is rotatably mounted on the upper surface of the valve lifter (3) in which the lobe (2) of the cam (1) is in contact, the lobe (2) by contacting the lobe (2) 2) and the valve lifter 3 is prevented from coming into direct contact.

To this end, in the valve structure of the present invention, as shown in FIG. 2, a completely spherical ball 4 is inserted on the upper surface of the valve lifter 3 so as to be rotatably mounted in the valve lifter 3. The lobe 2 of the cam 1 is mounted on the ball 4 so as to be in contact with the ball 4.

With this configuration, the lobe 2 is in contact with the ball 4 when the cam 1 rotates, and moves the entire valve up and down. At this time, the ball 4 is in contact with the lobe 2. ) Rotates in the same direction as the direction of rotation of the lobe 2, thereby reducing the friction between each other.

In addition, the cam 1, as shown in Figure 3, is formed to have a thickness smaller than the existing thickness, so that the contact area between the lobe 2 and the ball 4 of the cam 1 corresponds to one point To maintain a very small area.

As described above, according to the valve structure of the automobile engine, the lobe 2 is provided by providing a ball which can freely rotate on the upper end surface of the valve lifter 3 in contact with the lobe 2 of the cam 1. ) And the valve lifter are prevented from directly contacting each other, thereby preventing wear between each other.

In addition, there is an effect of reducing the weight of the camshaft as a whole by reducing the thickness of the cam (1).

On the other hand, the present invention is not limited to the above-described specific preferred embodiment, and any person having ordinary skill in the art to which the invention belongs without departing from the gist of the invention claimed in the claims, various changes Would be possible.

Claims (2)

In a valve structure of an automobile engine, the valve structure is integrally formed with a cam shaft and includes a cam having a lobe eccentrically to one side, and a valve lifter moved up and down by contacting the lobe of the cam at a lower part of the cam. A valve structure of an automobile engine, characterized in that a completely spherical ball is inserted in the upper surface and rotatably mounted in the valve lifter. 2. The valve structure of claim 1, wherein the cam and lobe are as thin as possible to reduce the contact surface with the ball mounted on the upper surface of the valve lifter.